It's a shame the HD20 is still such a Black Box type of device, even after those docs were posted. I know if I had one of those few Mac models that had a floppy port but no SCSI, I'd be doing a "The Scream" to the tune of "NOOOOOOO!" at the fact that BMOW's floppy-emu will not support this any time soon.

There's also the consideration that, given that such emulation would at some point need to be checked against the real deal, the window of opportunity for some Impressively Stubborn Researcher to figure it all out is rapidly closing as the world's supply of working HD20s evaporates due to age-related hardware failures.